6386 back in Production

[TheMIXIMAL]

on March 9th, we sent the following email to EveAnna Manley (have heard no reply yet, March 12th);



EveAnna,

We recently learned that JJ Electronic is now manufacturing 6386 tubes.
JJ-Electronic - Vacuum tubes, Capacitors, Amplifiers - Preamplifying tubes

We are interested in purchasing VariMu's later this year.
I personally fell in love with them a decade ago, and had two studios I was working in at the time purchase them (6386 models).


According to:
Manley_Variable_Mu®_Limiter_Compressor

"the availability of the 6386 is poor; we barely have any left at all"


Now that 6386 are again being manufactured, is there any chance of having one or two or five VariMu's built for the 6386 ?



best,



Justin
theMIXIMAL.com

[jensenmann]

Wait some more months and the cheapo fairchild clone with 6386s will be around. No need for Manleys anymore

[TheMIXIMAL]

Just heard back from EveAnna-- I sent the email incorrectly.
Not trying to get her in trouble-- just trying to see what was up.

[kafka]

Originally Posted by TheMIXIMAL

Just heard back from EveAnna-- I sent the email incorrectly.
Not trying to get her in trouble-- just trying to see what was up.

Well, just a wild guess here, but it's going to be some time before they'll be able to see if the new 6386's match the old, both in terms of performance and production. Moreover, since they have a solution based on dual 12BA6's that Manley says matches the original, the new 6386's will have to beat those.

Remember, Manley probably can't go into production based on a sample. They'll need to be able to supply replacements for decades to come. The new ones may be a good replacement, but the demand for these world wide will still be tiny. It may not be commercially feasible to keep up.

[streetvibes]

Good point kafka.

We have a newer Vari-Mu, but we just bought some 6386, plugged them in and did some trimming of meters and stuff. Sounds great.

[Matt Syson]

Hi
If these6386's have applications elsewhere they have a chance.
The whole of the certainly digital and to some extent of the analogue (IC amplifier) audio equipment is due to the scraps falling off the computer dining table.
IC 'op amps' were developed by the need for high gain versatile 'amplification units' needed for analogue computers. Audio people saw an opportunity and specialised them later.
Matt S

[Kronos147]

From the manufactures I have spoken to (very few, I admit), the concern is that with the price may still be prohibitive to use the new tubes. Look at a few GS threads and I see people trying to find a complete mic, compressor, or preamp for less money than a tube!

But, if each of us goes out and buys a pair of these tubes (or others) for future use, who knows, maybe JJ will prosper and they prices will come down.

I can cross my fingers anyway!

[Matt Syson]

Hi
There are far too many who want stuff 'on the cheap' but if you were to suggest halving or quartering the money they get for THEIR work they start to squeal for some reason!
Gear built in China is obscenely cheap and then people have the nerve to complain about quality.
We all have living costs to pay.
Matt S

[EveAnna Manley]

Apologies for my Auntie-Spaminal eating your first email up.

Speaking from the perspective of a manufacturer:

On the new JJ 6386, the first problem is the dang price! Retail price is $120 bucks??? And my wholesale cost ain't that much less.

So even to buy, say, 50 tubes to test and grade in order to form an opinion about them, we're looking at around $5000 bucks investment. I don't know about you guys, but we're in conservation mode right now in this economy. I'm not looking for extra expenses right now.

Anyway, suppose we get the tubes in and then, say we like them, and the yield is decent, now let's come up with tens of thousands of more dollars to get a couple hundred tubes in stock, which, depending on yield, and depending on demand, determined by price, which can't go too much higher than retail cost of the tubes to start with, and wholesale cost is not much less, why would I go through that huuuuuuuuuuuuuuuuuge investment and tie up massive amounts of cash to bless a tube that would make us an extra $20 or $40 net profit per Variable Mu® Limiter sold? (Presuming we make them an option and charge more for them, or just raise the price and charge more).

The number$ do not work for me to get involved to put this tube into production units, at this price structure.

I can't imagine in a couple of months looking at a reject tray of 100 tubes, tubes that were too noisy or whose two triodes don't match well enough to use them, and thinking, wow: look at that small pizza box of a hundred bad tubes worth $12,000! Will JJ take them back?

We have a sure and certain solution now with the 6BA6 T-Bar mod. They are reasonably priced tubes and easily available. I have thousands of them in stock and I have already invested in this solution. We get superb yield from them since most of them can find a friend, and find 3 other friends to be perfectly matched quad pairs in the units. The curves lay up almost exactly upon the 6386's curves. They function substantially the same, if not better due to the ability to perfectly match phase-halves and stereo sets instead of selecting for "decently" matched pairs in one glass bottle.

The 6BA6 T-Bar mod is proven and works great.

Nothing precludes end users from trying the new JJ 6386. If JJ wanted to send me 50 samples to test, bless (or reject), and return, we'd be happy to put the time in to see how tight their matching is and how quiet and lo-microphonic they are (or aren't). I just have no need to purchase a stock of tubes we will not be using in production at this time, tubes I cannot really turn a reasonable profit return on at this cost structure. If they were 1/10th or 1/20th of the cost, like all the other little dual triodes we use, maybe, sure. That wouldn't break the bank.

Remember I am speaking as a manufacturer about costing and business issues in this post and I am not judging the tubes themselves, having not tested any yet.

[Matt Syson]

Hi
One of my activities requires the selection of well matched valves. I buy a batch of supposedly pre matched specimens and from 20 get about 8 or so useable ones for this application. Fortunately they can be used unmatched for far more positions so it is not a significant loss apart from the extra time running them up, testing, burning in and retesting.
If they really are 120 Bucks for a valve with limited application it would be almost insane to contemplate their usage.
Matt S

[emrr]

Yes, $120 retail at Antique Electronics. Haven't seen them anywhere else yet. Funny thing is, it sure looks like they've made the bottom fall out of the over-inflated ebay vintage market.

[Kronos147]

Originally Posted by Kronos147

From the manufactures I have spoken to (very few, I admit)

Originally Posted by EveAnna Manley

Speaking from the perspective of a manufacturer:

Very nice of you to chime in here. One of the 'manufacturers' I had spoken with was your very own "Vacuum Tube Disciplinarian" when he came to my studio to resolve my non-issue (I can be dense sometimes.... ).

That is some great customer support, thanks kindly!

[mplancke]

Originally Posted by streetvibes

Good point kafka.

We have a newer Vari-Mu, but we just bought some 6386, plugged them in and did some trimming of meters and stuff. Sounds great.

No need for modifications to the circuit?

You can just plug em in, do the calibration procedure and go?

Mark

[mplancke]

Originally Posted by EveAnna Manley

Remember I am speaking as a manufacturer about costing and business issues in this post and I am not judging the tubes themselves, having not tested any yet.

Hi EveAnna

Aside from the quality issues, I'm curious if the JJ tubes are plug and play after following the calibration procedure in my Version 4 V-MU (#MSLC5710)

Mark

[EveAnna Manley]

Follow the directions below to convert your 5670-powered Manley Variable Mu® to use the 6386 tubes. It's more work to do this than to install our 6BA6 T-Bar mod kits which we charge $250 for (complete and installed with four 6BA6 tubes selected for quad-perfect matching, lo-noise, and lo-microphonics).

If you want us to convert your unit for you, we can. You'll be supplying the 6386 tubes and we will all pray to the Tube gods that they are quiet and internally matched. Maybe buy extras to be sure. Check out our service page for rates and then fill in the RA form to book the service and you can work with Paul on that.

INSTRUCTIONS FOR CONVERTING 5670 TO 6386


1) Replace 3k57 resistors connected to pins 4 & 6 of 5670 socket with 6k8 1W.

2) Replace 1k resistors connected to pins 2 and 8 with 511 ohms.

3) Replace 10k “balance” trimpot with 500 ohm trimpot.

4) Remove 200 ohm resistor between pins 2 and 8.

5) Replace 33k 1W resistor between wiper of “GR cal” trimpot and the junction of the meter with 22K 1W (resistor is located near the rear corner of the pcb next to the GR cal trimpot).

6) Repeat procedure for the other channel; re-calibrate as outlined in the owner’s manual.

[Reptil]

Originally Posted by jensenmann

Wait some more months and the cheapo fairchild clone with 6386s will be around. No need for Manleys anymore

the irony in your post (or lack of "iron" in a yet to be presented chinese clone) is noted. hearing is believing

[drtechno]

Ive used 6386 when building true balanced line stages and in reality there are several tubes out there that can be used, but it all boils down to the fact is that the dual triode sections need to match. I remember that there was trim adjustments in the Fairchild 660/670 for that reason.

what would be really cool is to come up with an auto bias scheme maybe with some op amps that balance the gain between the top and bottom tiode, therefore no calibration required.

I like the tone characteristics of the 60's NOS RCA 12AU7 built upon a true balanced line stage but I had to hand pick my tubes.

...What i mean about true balanced line stage is the positive signal input is going through active devices and the negative signal input is going through a mirrored set of active devices exactly like the positive signal path and none of the signal is truly referenced to any ac ground (dc supply or gnd).

[WTMNMF]

Originally Posted by EveAnna Manley

Apologies for my Auntie-Spaminal eating your first email up.

Speaking from the perspective of a manufacturer:

snip

Anyway, suppose we get the tubes in and then, say we like them, and the yield is decent, now let's come up with tens of thousands of more dollars to get a couple hundred tubes in stock, which, depending on yield, and depending on demand, determined by price, which can't go too much higher than retail cost of the tubes to start with, and wholesale cost is not much less, why would I go through that huuuuuuuuuuuuuuuuuge investment and tie up massive amounts of cash to bless a tube that would make us an extra $20 or $40 net profit per Variable Mu® Limiter sold? (Presuming we make them an option and charge more for them, or just raise the price and charge more).

The number$ do not work for me to get involved to put this tube into production units, at this price structure.

I can't imagine in a couple of months looking at a reject tray of 100 tubes, tubes that were too noisy or whose two triodes don't match well enough to use them, and thinking, wow: look at that small pizza box of a hundred bad tubes worth $12,000! Will JJ take them back?

snip

It seems to me that the standard approach here would be to make an arrangement with JJ for presorted tubes. Even if they wanted to increase the price by 50% or something for the service, it would be worth it and you would just adjust your price to reflect that. Were talking about rather pricey stuff to begin with here, so a 10 or 15% bump in the purchase price of a unit is not unreasonable.

[dale116dot7]

Originally Posted by drtechno

Ive used 6386 when building true balanced line stages and in reality there are several tubes out there that can be used, but it all boils down to the fact is that the dual triode sections need to match. I remember that there was trim adjustments in the Fairchild 660/670 for that reason.

what would be really cool is to come up with an auto bias scheme maybe with some op amps that balance the gain between the top and bottom tiode, therefore no calibration required.

One of the problems with bias is that in a compressor, the bias (and thus, operating point) changes with signal - so the bias to get the identical amount of gain in the top tube may be different than what is required in the bottom tube (for best distortion characteristics). Fair enough in a straight gain stage. But changing the bias point with operation (ie. when you change the CV in a compressor) is tricky because if you do that, you get a thump (CV feedthrough) if both the DC and AC gains don't match throughout pretty much the whole curve. You can tune for minimum thump and distortion between, say, 0dB and 10dB of reduction, but then as soon as you hit 15dB you motorboat. So tweak it in to increase distortion and you get 20dB without thumping but the THD at 0dB GR is about 15%. It's a no-win situation.

Although that Altec thump can be a neat effect on drums, that's what both tube selection and trims are for - to get rid of it. Some variable mu comps (based on 6SK7's and such) have plate load trims, cathode trims, and screen grid trims, to try to warp the curves to be useful - to get rid of both distortion and CV feedthrough.

In theory, an 'auto bias' circuit for a compressor would optimize the bias between the two halves, and also modify the application of the bias to minimize feedthrough. Trivial to do that with some kind of microcontroller, but isn't the simplicity of a tube compressor part of its beauty? Putting software in there just seems wrong to me.

[dale116dot7]

Originally Posted by WTMNMF

It seems to me that the standard approach here would be to make an arrangement with JJ for presorted tubes. Even if they wanted to increase the price by 50% or something for the service, it would be worth it and you would just adjust your price to reflect that. Were talking about rather pricey stuff to begin with here, so a 10 or 15% bump in the purchase price of a unit is not unreasonable.

But if you can make a unit that sounds as good (or maybe better) with xBA6 tubes for a fraction of the cost, and you can match tube pairs to get a very low rejection rate (instead of tossing a whole tube because the two halves don't match right), why wouldn't you just do it? Although the equipment I design does not require matching or component selection, I can very easily understand why there would be a reluctance to change something that's in production, works, sounds good, and offers a manufacturing advantage.

[yeloocproducer]

What's the consensus on the JJ tubes? Just wondering.

[ray_subsonic]

Bump ..

[lassoharp]

Originally Posted by yeloocproducer

What's the consensus on the JJ tubes? Just wondering.

Never tried them but Comment #8 from this thread is what I would expect.

J J Tubes 6386

i.e - acceptable which IMHO is the best you can ask for. When it comes to looking for the above and beyond . . I'd say it points to lemons as opposed to magic beans when that's observed.

At the prices they're charging I would contact JJ and find out what their policy on returns is and I wouldn't settle for anything less than 100% guaranteed for poor performers. For a reproduction tube aimed specifically at vintage vari-mu limiters, QC that doesn't involve testing critical in-circuit parameters doesn't seem to make sense. As was discussed earlier in the thread - why would anyone consider the risk of having to buy 30 tubes at that price and risk getting only 3 or 4 that are acceptable? The lemons should go to the crusher at the plant.

[Matt Syson]

Hi
While I agree to some point you would have to specify exactly WHICH vari mu unit you were wanting them for as the nature of valves is that the characteristics change with applied voltage and expected current. Just because the two 'halves' if the valve have equal characteristics in one application, if you change parameters they may well not be matched elsewhere.
Matt S
'Straight A star' graduate students and shoot all others that 'fail' the grades?

[Matthew Z]

Any new information from users of the JJ 6386 tube for the Manley Vari MU Compressor?!? I have an older Vari Mu - it is working great but I know some day my original 6386 will go bad:( Curious whether to go with the TBar mod or try a JJ6386 when that sad day comes... I would love to hear from anyone who has tried the JJ 6386 tube! thank you..